KEY POINTS:
8 is a lucky number for the Chinese and tonight the temperature is set to be 28 degrees at 8:08pm local time for the Olympic opening ceremony in Beijing.
The forecast is expected to be mostly sunny and sweltering with high humidity making it feel more like 34
degrees during the ceremony. Winds will be light and they'll be from the humid south east (like New Zealand's warm nor'west).
With humidity so high and winds so slow, there is the chance of some afternoon cloud build ups, but as luck would have it, there is an 80% chance of dry weather - there's that lucky number again! And one more stroke of good luck - our weather partner, weather.com, is expecting those light winds to be around 8km/h.
Apart from the polluting factories there's also a geographical reason for Beijing being so smoggy. Much like Christchurch, Beijing has mountains to one side. These mountains limit fronts that can zip through and "flush" the smog out to sea.
The Taihang mountains lie to the north and west of Beijing and when there's a large high over the city the smog gets trapped underneath it. The mountains act as a shelter belt blocking wind from moving in from the north west (like our strong sou'westers) and blowing that pollution away out to sea.
Most smoggy cities in the world suffer from the same geographical features - surrounding mountains that effectively 'shut off' the valve for air movement. It's also the reason why a lot of these places enjoy hot summers. Think Christchurch, Los Angeles, Mexico City even Alexandra.
Cities like Auckland, while much bigger than Alexandra, have the luxury of oceans on both sides. The wind constantly blows through and really most Aucklanders have no idea that there is a tonne of pollution being belched into the atmosphere every day.
When there's a big high pressure system over Auckland, and the wind has gone, you can see it. The sky, especially in the morning and evening when the sun is low and has to shine through more of the dirty atmosphere, is bronze and unhealthy looking.
With petrol prices on the increase, and Aucklands motorways becoming less clogged, the air quality should improve a little.
Anyway - good luck to all Kiwis competing in China - we wish you all the very best of, well...luck!
Philip Duncan
For the latest weather news keep up to date with The Radio Network's new Weather Watch Centre or the NZ Herald weather section.
Pictured above: A Chinese paramilitary police officer stands on duty near Olympic venues, the National Stadium, known as the Bird's Nest. (AP Photo / Andy Wong)
